Aim:
To find and extract data from original studies that assess the detection of transgenic DNA or newly expressed proteins in livestock animals fed with GMO-containing feeds.
Selection criteria:
In order to be included in the database a study needs to include each of the following criteria:
Relevant population(s): Cattle, pig, sheep, goat, poultry and fish.
Relevant exposure: Feed containing genetically modified organisms (GMO).
Relevant comparator: Feed containing the non-genetically modified conventional counterpart of the respective GMOs
Relevant outcomes: Any measurements of the presence or absence of transgenic DNA or newly expressed proteins in animal tissues, organs or fluids.
Search strategy:
The search of original research articles was performed using Scopus ( http://www.scopus.com ), a large abstract and citation database of peer-reviewed literature using the following search string: TITLE-ABS-KEY ( "genetically modified" OR "genetically engineered" OR biotech* OR transgenic ) AND TITLE-ABS-KEY ( cattle OR dairy OR cow* OR goat OR rabbit OR farm* OR fish OR poultry OR chicken OR hen OR pig* OR sheep OR calf ) AND TITLE-ABS-KEY ( fed OR feeding OR consumption OR diet ) AND TITLE-ABS-KEY ( maize OR corn OR rice OR soybean OR soya OR rapeseed OR potato )
Appling selection criteria:
One reviewer performed the selection of the studies, which fulfil the inclusion criteria at three stages. At first, articles are selected by their title to remove highly irrelevant studies from the overall search results, followed by the second stage in which the inclusion criteria are applied against the abstracts of the articles. In the third stage, the articles are reviewed in full text for the presence of each of the elements needed for the inclusion.
Data extraction:
Details about the performed experiment were extracted from the "Materials and Methods" section of the papers, while the measurements of the presence or absence of transgenic DNA or newly expressed proteins were extracted from the tables and graphs as provided by the authors in standardized data extraction sheet. Check for errors were performed on 20% subset of randomly selected records.
The following data extraction sheet was used:
|
Attribute |
Definition |
Type |
|
Animal |
Name of the animal |
Characters |
|
Animal_breed |
Name of the animal breed |
Characters |
|
Gender |
Name of the gender of the animal |
Characters |
|
Group_number |
Number of animal in the group for each treatment |
Number |
|
GM_crop |
Name of the crop |
Characters |
|
GM_trait |
Name of the GM trait |
Characters |
|
Inserted_gene |
Name of the inserted gene |
Characters |
|
GM_event |
Name of the GM event |
Characters |
|
Feed_type |
Name of the type of feed |
Characters |
|
GM_content_in_the_feed |
Percentage of GM material in the feed |
Number and characters |
|
Duration |
Period in which animals have been fed with GM feed |
Number and characters |
|
Time_point_of_sampling |
Time point of the sampling from the beginning of the experiment |
Number and characters |
|
Detection_method |
Name of the method used for detection |
Characters |
|
Measurement_endpoint |
Name of measured endpoint such as DNA or protein |
Characters |
|
Probes_for_detection |
Name of probes used for detection |
Characters |
|
Type_of_sample |
Name of the type of the sample such as blood digesta content, egg excreta, milk, muscule tissue |
Characters |
|
Sample |
Name of the sample |
Characters |
|
Measurement_units |
Name of experiment outcome measurement |
Characters |
|
GM_treatment |
Measured outcome for the GM treatment |
Characters |
|
NonGM_treatment |
Measured outcome for the non-GM treatment |
Characters |
|
References |
Any information which may be relevant |
Characters |
|
Full_references |
Bibliographic reference |
Characters |
|
Source |
Table or figure from which the data originates |
Characters |
|
Link_to_publication |
Web link or DOI to the publication |
Characters |
